Alkoxylated aromatic amine-aromatic polyester polyol blend and polyisocyanurate foam therefrom

ABSTRACT

Polyisocyanurate foams are prepared by reacting together an organic polyisocyanate, a blowing agent, a trimerization catalyst, and a minor amount of a polyol blend comprising 
     (a) about 5 percent to about 95 percent by weight of said blend of an alkylene oxide adduct of an aromatic amine of the formula ##STR1##  wherein Z is a divalent aromatic radical, x, x&#39;, y, and y&#39; each independently have an average value from about 1 to about 5, and each R is independently selected from the group consisting of hydrogen, alkyl or aryl, provided that the adduct is capped with ethylene oxide units, and 
     (b) about 5 percent to about 95 percent by weight of said blend of an aromatic polyester polyol material having a molecular weight of from about 150 to about 5,000. Laminates of such foams exhibit a high degree of fire resistance, low foam friability, high compressive strength, and excellent facer adhesion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the preparation of a laminate using apolyisocyanurate foam as a core material. The foam is produced from anorganic polyisocyanate and a polyol blend comprising (a) an alkyleneoxide adduct of an aromatic amine capped with primary hydroxyl groups,and (b) an aromatic polyester polyol material.

2. Description of the Prior Art

Polyisocyanurate foams are well known and are described, for example, inU.S. Pat. Nos. 3,799,896 and 3,940,517 and in U.K. Pat. No. 1,155,768.It is also known to employ polyisocyanurate foams as the core oflaminated foam board stock material which can be prepared with a varietyof different facer materials, as described, for example, in U.S. Pat.No. 3,940,517, supra. Unfortunately, the adhesion of the facer materialto the foam core has not been as great as desired. Poor facing sheetadhesion can result in delamination.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an improvedpolyisocyanurate foam having a combination of advantageous properties,including a reduced friability and high thermal stability andcompressive strength, and a method of producing the foam.

It is another object of the present invention to provide apolyisocyanurate foam which has improved facing sheet adhesion withoutadversely affecting the other physical and chemical properties of thefoam.

It is still another object of the present invention to produce animproved laminate having a facing sheet which adheres tenaciously to apolyisocyanurate foam core without altering other advantageousproperties of the foam, such as a low friability and flammability.

It is a further object of the present invention to provide an efficient,energy saving process requiring reduced production time and curetemperatures for producing a laminate of a polyisocyanurate foam havingimproved facing sheet adhesion and moldability, while maintaining otheradvantageous physical properties of the laminate, such as superior fireresistant properties, which would qualify for approval by the FactoryMutual Research Corporation, as, e.g., a Class I rating in the FactoryMutual calorimeter test for roof insulation products.

It is a still further object of the present invention to provide apolyol blend for use in preparing polyisocyanurate foams of reducedfriability, high thermal stability and compressive strength, andexcellent facer adhesion.

These and other objects and advantages of the present invention willbecome more apparent by reference to the following detailed descriptionand drawing which is a side schematic representation of an apparatussuitable for producing a polyisocyanurate foam material in accordancewith the present invention.

DESCRIPTION OF THE INVENTION

The above objects have been achieved and the drawbacks of the prior arthave been overcome by the development of an improved polyisocyanuratefoam, which is prepared by reacting an organic polyisocyanate with apolyol blend comprising (a) an alkylene oxide adduct of an aromaticamine capped with ethylene oxide, and (b) an aromatic polyester polyolmaterial in the presence of a blowing agent and a catalyst(s).

Component (a) of the polyol blend of the invention comprises from about5 percent to about 95 percent by weight of said blend of an additionproduct of an aromatic amine with an alkylene oxide or mixture ofalkylene oxides. The adduct may be represented by the formula ##STR2##wherein Z is a divalent aromatic radical which can be substituted orunsubstituted, x, x', y, and y' each independently have an average valuefrom about 1 to about 5, and each R is independently selected from thegroup consisting of hydrogen, alkyl or aryl, provided that the adduct iscapped with ethylene oxide units. The group Z may be selected from axylylene group, arylene groups selected from ortho, meta or paraphenylene, xylene, tolylene, biphenylene, naphthylene or anthrylene, ora substituted arylene group of the formula ##STR3## wherein W is acovalent bond, sulfur, carbonyl, --NH, --N--(lower)alkyl, O, S, SS,--N-phenyl, sulfonyl, a linear or branched alkylene group of from 1 to 3carbon atoms, arylene, especially phenylene group, or a dialkyl ordiaryl silyl group, and R₁ and R₂ are independent and each is hydrogen,halogen, especially chloro or bromo, lower alkyl from 1 to 5 carbonatoms, especially methyl, lower alkoxy containing from 1 to 5 carbonatoms, especially methoxy, or aryl, especially phenyl.

Examples of alkoxylated aromatic amines useful in the present inventionare the alkoxylated adducts of 4-chloro-o-phenylenediamine,4-chloro-m-phenylenediamine, 3,3'-diaminobenzidine, 2,4-diaminotoluene,2,6-diaminotoluene, 3,4-diaminotoluene, 4,5-dichloro-o-phenylenediamine,4,5-dimethyl-o-phenylenediamine, 4-methoxy-o-phenylenediamine,4,4'-methylenebis-(o-chloroaniline), 4,4'-methylenedianiline,4,4'-methylenebis-(3-nitroaniline), 2-nitro-p-phenylenediamine,o-phenylenediamine, m-phenylenediamine, p-phenylenediamine and1,5-diaminonaphthalene.

A preferred alkoxylated aromatic amine of the blend is an ethylene oxideadduct of toluene diamine isomers of the formula ##STR4## wherein theaverage number of oxyethylene units per polyoxyethylene chain is from 2to 3. An example of a suitable, commercially available aromatic-aminopolyether polyol of the blend is the product sold by BASF WyandotteCorporation under the trademark Pluracol® Polyol 735.

The polyols of component (a) of the blend can be produced by adding analkylene oxide to an aromatic amine in the presence of an acid or alkalicatalyst. Any suitable alkylene oxide or mixture of alkylene oxides canbe used in the preparation of the adduct, such as, for example, ethyleneoxide, 1,2-propylene oxide, 1,2-butylene oxide, and the like, providedthat the adduct is capped with ethylene oxide units to provide terminalprimary hydroxyl groups. The polyols of component (a) can be used aloneor as a mixture thereof. The OH value of the polyol can be varied bycontrolling the amount of alkylene oxide added during the synthesis. Thealkoxylated aromatic amines generally have a hydroxyl equivalent weightof from about 75 to 250, preferably from about 100 to 150.

The polyols of component (b) of the blend comprise polyesters containingat least two hydroxyl groups, which generally have a molecular weight offrom about 150 to 5,000. Preferably, the polyesters contain from 2 to 8hydroxyl groups and have a molecular weight of from about 220 to 800,more preferably from about 270 to 400. The acid component of thesepolyesters comprises at least 40% by weight of phthalic acid residues.By phthalic acid residue is meant the group ##STR5##

These polyesters include, for example, reaction products of polyhydric,preferably dihydric and optionally trihydric, alcohols with phthalicacids and other polybasic, preferably dibasic, carboxylic acids. Insteadof using the free phthalic acids or polycarboxylic acids, thecorresponding acid anhydrides or corresponding acid esters of loweralcohols or mixtures thereof may be used for preparing the polyesters.O-phthalic acids, isophthalic acids and/or terephthalic acids may beused as the phthalic acid. The optional polybasic-carboxylic acids maybe aliphatic, cycloaliphatic, aromatic and/or heterocyclic and may besubstituted, for example, with halogen atoms and/or may be unsaturated.The following are mentioned as examples: succinic acid, adipic acid,suberic acid, azelaic acid, sebacic acid, trimellitic acid,tetrahydrophthalic acid anhydride, hexahydrophthalic acid anhydride,endomethylene tetrahydro phthalic acid anhydride, glutaric acidanhydride, maleic acid, maleic acid anhydride, fumaric acid, dimeric andtrimeric fatty acids, such as oleic acid, optionally mixed withmonomeric fatty acids. Suitable polyhydric alcohols include, forexample, ethylene glycol, propylene glycol-(1,2) and -(1,3), octanediol-(1,8), neopentyl glycol, cyclohexane dimethanol,(1,4-bis-hydroxymethylcyclohexane), 2-methyl-1,3-propane diol, glycerol,trimethylolpropane, hexanetriol-(1,2,6), butane triol-(1,2,4),trimethylolethane, pentaerythritol, quinitol, mannitol and sorbitol,methylglycoside, diethylene glycol, triethylene glycol, tetraethyleneglycol, polyethylene glycols, dipropylene glycol, polypropylene glycols,dibutylene glycol, and polybutylene glycols. The polyesters may alsocontain carboxyl end groups. Polyesters of lactones, such asε-caprolactone, or hydroxycarboxylic acids, such as ω-hydroxycaproicacid, may also be used.

A preferred hydroxy terminated aromatic polyester for use as component(b) in the present invention is prepared by the transesterification,with a glycol of molecular weight from about 60 to about 400, of aresidue remaining after dimethyl terephthalate and methyl p-toluate havebeen removed from a dimethyl terephthalate esterified oxidate reactionproduct, the major portion of said residue comprising a mixture ofmethyl and benzyl esters of benzene and biphenyl di- and tricarboxylicacids. This residue is described in U.S. Pat. No. 3,647,759, thedisclosure of which is hereby incorporated by reference. Two preferredtransesterifying glycols which can be reacted with the residue areethylene glycol and diethylene glycol, with the latter being morepreferred. Examples of transesterified residues which can be used inaccordance with the invention are those supplied by Hercules, Inc.,Wilmington, Del. under the trade name of Terate® resins.

An excess of the transesterifying glycol advantageously may be used toreact with the residue defined above. The amount of this preferredexcess of transesterifying glycol remaining in the transesterifiedpolyol mixture can vary broadly but suitably falls within a range offrom about 5 to about 30 percent by weight of said polyol mixture.

The properties of the transesterified polyol mixtures which can beemployed as component (b) in accordance with the present invention fallwithin rather broad ranges. The polyol mixtures are described in U.S.Pat. No. 4,237,238, the disclosure of which is hereby incorporated byreference. A preferred polyol mixture is characterized by a viscosity incps at 25° C. of about 1,600 to about 2,800, a free diethylene glycolcontent of from about 20 to about 30 percent by weight of said mixture,a hydroxyl number within a range of from about 400 to about 490, and anacid number of about 0.2 to about 8.

Another preferred aromatic polyester polyol material which can beemployed as component (b) of the polyol blend of the invention isprepared by the transesterification, with a glycol of molecular weightfrom about 60 to 400, of a by-product fraction from the manufacture ofdimethyl terephthalate, the major portion of said fraction comprisingabout 15 to 70 weight percent of dimethyl terephthalate, and about 85 to30 weight percent of a mixture of monomethyl terephthalate, bi-ringesters and polymeric materials. An expecially useful polyol mixture canbe prepared by transesterifying a by-product fraction from themanufacture of dimethyl terephthalate comprising a mixture of

(a) about 40 to 60 percent by weight of dimethyl terephthalate,

(b) about 1 to 10 percent by weight of monomethyl terephthalate,

(c) about 1 to 2 percent by weight of terephthalic acid,

(d) about 10 to 25 percent by weight of bi-ring esters,

(e) about 5 to 12 percent by weight of organic acid salts,

(f) about 18 to 25 percent by weight of polymeric materials, and

(g) about 1 to 4 percent by weight of ash. An excess of thetransesterifying glycol is advantageously used to react with theby-product fraction. Two preferred glycols for transesterifying theby-product fraction are ethylene glycol and diethylene glycol, with thelatter being more preferred. An example of a transesterified by-productfraction of the invention is the product supplied by Jim WalterResources, Inc. under the trade designation Foamol 250.

The properties of the polyol mixture produced by transesterifying theby-product fraction defined above are described in U.S. Pat. No.4,411,949, the disclosure of which is hereby incorporated by reference.A preferred polyol mixture is characterized by a viscosity in cps at 25°C. of about 700 to about 2500, a free diethylene glycol content of fromabout 10 to about 30 percent by weight of said mixture, a hydroxylnumber within a range of from about 350 to about 468, and an acid numberof about 0.2 to about 10.

Other desirable aromatic polyester polyol materials for use in thepresent invention are those described in U.S. application Ser. No.372,904, filed Apr. 29, 1982, the disclosure of which application ishereby incorporated by reference.

The polyol blend containing components (a) and (b) can be obtainedsimply by mixing together, at the time of use in producing the rigidpolyisocyanurate foam of the invention, the individual components (a)and (b), which are synthesized separately prior to use. Preferably, thealkoxylated aromatic amine is employed within a range of from about 10to 50, more preferably about 20 to 40, percent by weight of the blendwhile the aromatic polyester polyol material is employed within a rangeof from about 50 to 90, more preferably about 60 to 80, percent byweight. A preferred polyol blend of the invention comprises about 30percent by weight of the ethoxylated aromatic amine, Pluracol® Polyol735, and about 70 percent by weight of the aromatic polyester polyolmaterial, Foamol 250. The blend is a liquid having a hydroxyl number of362-415 and a Brookfield viscosity at 25° C. of 2300-2950. Anotherpreferred blend comprises about 25 percent by weight of Pluracol® Polyol735 and about 75 percent by weight of the aromatic polyester polyolmaterial supplied by Hercules Inc. under the trademark "Terate 202".

In the broadest aspects of the present invention, any organicpolyisocyanate can be employed in the preparation of the foams of thepresent invention. The organic polyisocyanates which can be used includearomatic, aliphatic and cycloaliphatic polyisocyanates and combinationsthereof. Representative of these types are the diisocyanates such asm-phenylene diisocyanate, toluene-2,4-diisocyanate,toluene-2,6-diisocyanate, mixtures of 2,4- and 2,6-toluene diisocyanate,hexamethylene-1,6-diisocyanate, tetramethylene-1, 4-diisocyanate,cyclohexane-1,4-diisocyanate, hexahydrotoluene 2,4- and2,6-diisocyanate, naphthalene-1, 5-diisocyanate,diphenylmethane-4,4'-diisocyanate, 4,4'-diphenylenediisocyanate,3,3'-dimethoxy-4,4'-biphenyldiisocyanate,3,3'-dimethyl-4,4'-biphenyldiisocyanate, and3,3'-dimethyldiphenylmethane-4,4'-diisocyanate; the triisocyanates suchas 4,4',4"-triphenylmethanetriisocyanate, polymethylenepolyphenylisocyanate, toluene-2,4,6-triisocyanate; and the tetraisocyanates suchas 4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate. Theseisocyanates are prepared by conventional methods known in the art suchas the phosgenation of the corresponding organic amine.

In a preferred rigid foam of the invention, the organic polyisocyanateis polymethylene polyphenylisocyanate. The polymethylenepolyphenylisocyanates desirably have a functionality of at least 2.1 andpreferably 2.5 to 3.2. These preferred polymethylenepolyphenylisocyanates generally have an equivalent weight between 120and 180 and preferably have an equivalent weight between 130 and 145.The friability of foams made with these polyisocyanates is desirablyless than 30%, preferably less than 20%.

A preferred subclass of polymethylene polyphenylisocyanates especiallyuseful in the present invention is a mixture of those of the followingformula: ##STR6## wherein n is an integer from 0 to 8 and wherein themixture has the above-described functionality and equivalent weight.This mixture should have a viscosity between 100 and 4,000 andpreferably 250 to 2500 centipoises measured at 25° C. in order to bepractical for use in the present invention.

Examples of suitable polymethylene polyphenylisocyanates useful in thepresent invention include those of the above formula, wherein n is 1 aswell as mixtures wherein n can have any value from 0 to 8 as long as themixture has the specified equivalent weight. One such mixture has 40weight percent of n=0, 22 weight percent of n=1, 12 weight percent ofn=2, and 26 weight percent of n=3 to about 8. The preferredpolymethylene polyphenyl isocyanates are described in U.S. applicationSer. No. 322,843, filed Jan. 11, 1973, now abandoned. The synthesis ofpolymethylene polyphenylisocyanates is described in Seeger et al., U.S.Pat. No. 2,683,730 and in Powers U.S. Pat. No. 3,526,652 at column 3,lines 6-21. It should, therefore, be understood that the polymethylenepolyphenylisocyanates available on the market under the tradenames ofCODE 047 or PAPI-20 (Upjohn) and Mondur MR-200 (Mobay) can successfullybe employed within the spirit and scope of the present invention.

In order to ensure complete reaction, the polymethylenepolyphenylisocyanate and the polyol blend are generally mixed in anequivalent ratio of 1.5:1 to 6:1 and preferably 2:1 to 5:1. In rangesoutside these proportions the reaction yields a product havingundesirable physical characteristics. At higher ratios the product hasan undesirably high friability. At lower ratios the product has anundesirably high flammability.

In the preparation of these polyisocyanurate rigid foams, any catalystsknown to catalyze the trimerization of isocyanates to formisocyanurates, and to catalyze the reaction of isocyanate groups withhydroxyl groups to form polyurethanes, can be employed. The preferredcatalysts give cream times of 15 to 30 seconds and firm times of 25 to80 seconds. One preferred type of catalyst is a mixture of a tertiaryamino phenol, such as 2,4,6-tris(dimethylaminomethyl)phenol, and analkali metal carboxylate, such as potassium-2-ethyl hexoate, thesynthesis and use of which are described in U.S. Pat. No. 4,169,921. Thedisclosure of this patent is hereby incorporated by reference. Theequivalent ratio of tertiary amino phenol to alkali metal carboxylate inthe cocatalyst composition is desirably about 0.4:1 to 2.5:1. Anothercatalyst system is that employing an epoxide, an N-substitutedaziridine, and a tertiary amine. The synthesis and use of such acatalyst are described in U.S. application Ser. No. 251,279, filed May8, 1972, now U.S. Pat. No. 3,799,896. The catalysts generally comprisefrom 0.1 to 20 and preferably from 0.3 to 10 weight percent of the totalcomposition.

Any blowing agent typically employed in similar prior art foam productscontaining polyisocyanurate linkages can be employed in the foamcompositions of the present invention. In general, these blowing agentsare liquids having a boiling point between minus 50° C. and plus 100° C.and preferably between 0° C. and 50° C. The preferred liquids arehydrocarbons or halohydrocarbons. Examples of suitable blowing agentsinclude, among others, chlorinated and fluorinated hydrocarbons such astrichlorofluoromethane, CCl₂ FCClF₂, CCl₂ FCF₃, diethylether, isopropylether, n-pentane, cyclopentane, and 2-methylbutane.Trichlorofluoromethane is a preferred blowing agent. The blowing agentsare employed in an amount sufficient to give the resultant foam thedesired bulk density which is generally between 0.5 and 10, andpreferably between 1 and 5 pounds per cubic foot. The blowing agentgenerally comprises from 1 to 30, and preferably comprises from 5 to 20weight percent of the composition. When the blowing agent has a boilingpoint at or below ambient, it is maintained under pressure until mixedwith the other components. Alternatively, it can be maintained atsubambient temperatures until mixed with the other components.

Any suitable surfactant can be employed in the foams of this invention.Successful results have been obtained with silicone/ethyleneoxide/propylene oxide copolymers as surfactants. Examples of surfactantsuseful in the present invention include, among others,polydimethylsiloxane-polyoxyalkylene block copolymers available from theUnion Carbide Corporation under the trade names "L-5420" and "L-5340"and from the Dow Corning Corporation under the trade name "DC-193".Other suitable surfactants are those described in U.S. Pat. No.4,365,024 and U.S. application Ser. No. 490,279, filed May 2, 1983.Generally, the surfactant comprises from about 0.05 to 10, andpreferably from 0.1 to 6, weight percent of the foam-formingcomposition.

Other additives may also be included in the foam formulations. Includedare flame retardants, such as tris(2-chloroethyl)-phosphate, dispersingagents, plasticizers, fillers and pigments.

The polyisocyanurate foams of the present invention are simply producedby mixing the components with the result that foaming and curing takeplace. The mixing can be accomplished at 0° to 50° C., and preferably at10° to 30° C. The process can be practiced as a batch or continuously.

The laminate of the present invention can be formed by contacting thefoaming mixture with any of the sheet materials or facers conventionallyemployed in laminated foam insulation products. Such facing materialsinclude, but are not limited to, metal, paper, corrugated cardboard,plastics, wood, glass and textiles. In some cases, adhesion can beimproved by coating the facing materials before lamination withconventional coating compositions such as vinyl or epoxy compounds.Particularly suitable facers for use in the invention are asphalt fiberglass facers, asphalt-saturated roofing felt, perlite board, aluminumfoil, and fiberboard.

Referring now to the drawing, there is shown schematically an apparatussuitable for use in connection with the present invention. The apparatuscomprises an isocyanate tank 10, a polyol tank 11, and a catalyst tank12, each respectively connected to outlet lines 13, 14, and 15. Thetemperatures of the ingredients are controlled to ensure satisfactoryprocessing. The lines 13, 14, and 15 form the inlet to metering pumps16, 17, and 18. The pumps 16, 17, and 18 discharge respectively throughlines 19, 20, and 21 which are in turn respectively connected toflexible lines 22, 23, and 24. The flexible lines 22, 23, and 24discharge to mixing head 25. The apparatus is also provided with a roll26 of lower facing sheet material and a roll 26' of upper facing sheetmaterial. The apparatus also can be provided with a roll 27 of glassfiber mat material when it is desired to reinforce the structurallaminate. The apparatus also includes metering rolls 28 and 29, and anoven 30 provided with vents 31, 31' for blowing hot air. Lower and upperendless conveyors 32 and 33 are positioned in oven 30 to contain theexpanding foam. Both endless conveyors 32 and 33 can comprise a seriesof articulated platens, such as described in U.S. Pat. No. 4,043,719,the disclosure of which is incorporated herein by reference. Theapparatus is also provided with pull rolls (not shown) for pulling thefacing sheets and optional glass fiber mat through the apparatus, andcutting means 34. In another embodiment of the invention, a rigid facersuch as perlite board is continuously conveyed along the production linein place of the lower facing sheet material. The individual perliteboards are transported along the line by means of conveyor rollers (notshown).

In operation, the isocyanate tank 10 is charged with an organicpolyisocyanate admixed with a blowing agent and surfactant, and thepolyol tank 11 is charged with the polyol blend of the invention, andthe catalyst tank 12 is charged with a catalyst composition. The speedsof the pumps 16, 17, and 18 are adjusted to give the desired ratios ofthe ingredients in the tanks 10, 11, and 12. These ingredients passrespectively through lines 19, 20, and 21 as well as lines 22, 23, and24, whereupon they are mixed in the mixing head 25 and dischargedtherefrom. Optionally, lines 20 and 21 can feed into a single conduitfor delivery to the mixing head. By virtue of rotation of the pullrolls, lower facing sheet 35 is pulled from the roll 26, and upperfacing sheet 35' is pulled from the roll 26', and, when applicable,glass fiber mat 36 is pulled from the roll 27. The facing sheet andglass fiber mat materials pass over idler rollers such as idler rollers37 and 38 and are directed to the nip between metering rolls 28, 29. Themixing head 25 is caused to move back and forth, i.e., out of the planeof the paper by virtue of its mounting on a reciprocating mechanism (notshown). In this manner, an even amount of material can be maintainedupstream of the nip between the metering rolls 28, 29. The compositestructure at this point now comprising a lower facing sheet 35, an upperfacing sheet 35' on either side of a foam-forming mixture 39 andoptionally a mat 36 of glass fibers, now passes into the oven 30. Whilein the oven 30 the foam-forming mixture expands under the influence ofheat added by the hot air from vents 31, 31' and due to the heatgenerated in the exothermic reaction between the polyol blend and theisocyanate in the presence of the catalyst. As the foam expandsupwardly, it comes into contact with upper facing sheet 35', forcing thesheet against conveyor 33 and causing the sheet to assume asubstantially planar disposition on the upper correspondingly planarsurface of the foam. The temperature within the oven is controlled byvarying the temperature of the hot air from vents 31, 31', in order toinsure that the temperature within the oven 30 is maintained within thelimits necessary to cure the foam employed, as, e.g., from 100° F. to350° F. and preferably 150° F. to 250° F. The structural laminate 40then leaves the oven 30, and is cut by cutting means 34 into individualpanels 41, 41'.

While the structural laminate of the invention can contain variousreinforcement materials, in a preferred embodiment glass fiber mat 36comprises a thin, substantially incompressible yet expansible mat ofglass fibers, as described in U.S. Pat. Nos. 4,118,533 and 4,284,683,the disclosures of which are hereby incorporated by reference. This thinmat 36 of glass fibers is distinguished by having the fibers arranged inlayers, and the fibers within each layer are long, generally having alength greater than one foot and preferably 5 to 12 feet, and at anangle to the fibers in each next adjacent layer. Before passing throughthe nip of the metering rolls, thin fiber mat 36 is advantageouslypassed through intermeshing corrugated rolls (not shown), which effect atransverse stretching of the mat, as described in U.S. Pat. No.4,346,133. When the mat 36 of glass fibers thereafter passes through thenip between the two rotating metering rolls 28 and 29, pressure isapplied to the mat by the metering rolls, causing the foam-formingmixture 39 to penetrate the interstices between the glass fibers formingthe mat. After passing through the nip, the glass fibers expand underthe influence of the expansion of the foam-forming mixture 39 and becomedistributed in the foam core of the structural laminate.

Numerous modifications to the apparatus will be immediately apparent tothose skilled in the art. For example, the tanks 10, 11, and 12 can beprovided with refrigeration means in order to maintain the reactants atsubambient temperatures.

The use of aromatic polyester polyol materials as the polyol componentin the manufacture of polyisocyanurate foam laminates can result in poorfacer adhesion during the time period immediately following productionof the laminate. This can bring about handling problems and delaminationof the facers. While the adhesion may be improved by further heattreatment and/or storage of the laminate, employment of the inventivepolyol blend makes it possible to produce polyisocyanurate foamlaminates whose facers already strongly adhere to the foam core rightafter production, without the extra time and expense required in thecase of laminates based solely on aromatic polyester polyol materials.

The invention is further illustrated by the following example in whichall parts and percentages are by weight unless otherwise indicated.

EXAMPLE

This example illustrates the process of the present invention and acomparative process for producing structural laminates by reference tothe drawing.

A ISOCYANURATE FORMULATIONS USED IN PREPARING FOAM CORE OF STRUCTURALLAMINATES

The inventive polyol blend and a comparative aromatic polyester polyolmaterial were employed in preparing the foam cores of the structurallaminates of the following Table II, utilizing the inventiveisocyanurate formulations 1 to 4, and comparative isocyanurateformulations 5 and 6 of the following Table I.

B PRODUCTION OF STRUCTURAL LAMINATES

The production of each structural laminate can be illustrated withreference to the drawing. For each laminate, items A, G and H of therespective formulation were mixed with each other and placed in tank 10.Items B and C, in the case of each inventive formulation, were mixed andplaced in tank 11, whereas, in the case of the comparative formulations,item B alone was placed in tank 11. The catalytic composition comprisinga solution of items D and E in items F and F' or F alone (inventiveformulation 2) was placed in tank 12 in the production of each laminate.Table II below shows for the production of each of laminates A to F thetop and bottom facers utilized, the quantity of reinforcing glass fibermat utilized, and the oven temperature. For each run, the apparatus wasprovided with rolls 26', 26 of the top and bottom facers, and a roll 27of glass fiber mat material. The mat 36 of glass fibers wassubstantially incompressible. The glass fibers forming the mat werelong, generally straight fibers having an average diameter of less than25 microns and lengths varying from 5 to 12 feet with an average lengthof over 5 feet.

With the oven 30 heated to an appropriate temperature, the facers andglass fiber mat were fed toward the nip of metering rolls 28 and 29, andthe pumps 16, 17 and 18 were started to discharge the contents of thetanks 10, 11 and 12 into the respective feed lines to carry theingredients to the mixing head 25. The glass fiber mat was stretched bybeing passed through a pair of intermeshing corrugated rolls to effect arupture of some of the fiber to fiber bonds. The mixing head 25deposited the foam forming mixture onto the lower facer and both upperand lower facers, glass fiber mat, and foamable mixture were thenconveyed into the oven 30 to produce each of laminated structural panelsA to F.

Various properties of the resulting structural laminates are reported inTable III below. The physical property data presented in Table IIIreveal that use of the aromatic-amino polyether polyol in combinationwith the aromatic polyester polyol material used in preparing the foamcore of comparative structural laminates E and F has no adverse effecton resulting inventive structural laminates A to D. Most importantly,the inventive structural laminates displayed a facer adhesion which wasfar superior to that of the laminates made with an aromatic polyesterpolyol material as the sole polyol, indicating that the aromatic-aminopolyether polyol is eminently suitable to partially replace thepolyester polyol in the production of structural laminates.

                                      TABLE I                                     __________________________________________________________________________                         INVENTIVE FORMULATIONS                                                                         COMPARATIVE FORMULATIONS                                     1   2    3   4   5         6                             Item                                                                             Ingredient        (parts by weight)                                                                              (parts by weight)                       __________________________________________________________________________    A  Polymethylene polyphenyl                                                                        206 213  206 206 220       220                              isocyanate.sup.1                                                           B  Aromatic polyester polyol material.sup.2                                                        67.2                                                                              60.9 51.8                                                                              43.1                                                                              80        80                            C  Aromatic-amino polyether polyol.sup.3                                                           28.8                                                                              26.1 22.2                                                                              18.5                                                                              --        --                            D  2,4,6-tris(dimethylaminomethyl)                                                                 .83 .77  .83 .83 .83       .83                              phenyl.sup.4                                                               E  Potassium-2-ethyl hexoate.sup.4                                                                 1.75                                                                              3.24 1.75                                                                              1.75                                                                              1.75      1.75                          F  Diethylene glycol.sup.4                                                                         .75 6.0  .75 .75 .75       .75                            F.sup.1                                                                         Polyoxyethylene glycol.sup.4                                                                    6.67                                                                              --   6.67                                                                              6.67                                                                              6.67      6.67                          G  CFCl.sub.3        55.5                                                                              55.5 55.5                                                                              55.5                                                                              55.5      55.5                          H  Polydimethylsiloxane polyoxy-                                                                   3.5 3.5  3.5 3.5 3.5       3.5                              alkylene copolymers.sup.5                                                  __________________________________________________________________________     .sup.1 Item A is a polymethylene polyphenyl isocyanate having an              equivalent weight of 138, an acidity of 0.03% HCl, and a viscosity of 200     centipoises at 25° C. and is available from the Mobay Chemical         Company, Pittsburgh, Pa. under the trade name MONDUR MR200.                   .sup.2 Item B is that supplied by Jim Walter Resources, Inc. under the        trade name Foamol 250.                                                        .sup.3 Item C is that supplied by BASF Wyandotte Corporation under the        trade name Pluracol ® Polyol 735.                                         .sup.4 Items D and E are employed in the form of a solution in the            diethylene glycol (item F) and polyoxyethylene glycol (item F'), or, in       the case of formulation 2, in the diethylene glycol only.                     .sup.5 Item H is a surfactant supplied by the Union Carbide Corporation       under the trade name L5340.                                              

                                      TABLE II                                    __________________________________________________________________________    PRODUCTION OF STRUCTURAL LAMINATES                                            Structural                                                                          Formulation              Glass Fiber                                                                          Oven                                    Laminate                                                                            Utilized                                                                             Facers*           Mat (gm/ft.sup.2)                                                                    Temp. (°F.)                      __________________________________________________________________________    A     1      Asphalt-saturated roofing felt                                                                  4.0    190                                     B     2      Fiber glass coated on both sides with                                                           5.6    160                                                  clay-filled asphalt emulsion                                     C     3      Fiber glass coated on both sides with                                                           4.0    225                                                  clay-filled asphalt emulsion                                     D     4      Fiber glass coated on both sides with                                                           "      225                                                  clay-filled asphalt emulsion                                     E     5      Asphalt-saturated roofing felt                                                                  "      180                                     F     6      Fiber glass coated on both sides with                                                           "      210                                                  clay-filled asphalt emulsion                                     __________________________________________________________________________     *All laminates faced on top and bottom by facing material shown.         

                                      TABLE III                                   __________________________________________________________________________    PROPERTIES OF STRUCTURAL LAMINATES                                                                              Compressive                                 Structural                                                                          Thickness                                                                           Density                                                                            Oxygen                                                                             Closed                                                                              Friability.sup.4                                                                    Strength.sup.5                              Laminate                                                                            (in)  (lb/ft.sup.3)                                                                      Index.sup.2                                                                        Cells (%).sup.3                                                                     (%)   (p.s.i.)                                                                             Adhesion.sup.6                       __________________________________________________________________________    A     1.4   2.25 22.8 91.0   5.0  21.9   Very good                             B.sup.1                                                                            3.0   2.02 --   87.6  --    --     "                                    C     1.2   2.01 23.2 89.6  10.3  25.9   "                                    D     1.2   2.09 24.8 88.0  12.1  20.9   "                                    E     1.4   2.43 23.1 90.6   7.4  24.5   Poor                                 F     1.4   2.35 23.9 89.3  11.7  20.8   "                                    __________________________________________________________________________     .sup.1 Received a Class I rating in the Factory Mutual calorimeter            .sup.2 Flammability test conducted according to ASTM D2863-70, except tha     a sample measuring 1/2" × 1/2" × 6" was                           .sup.3 According to ASTM Test Method                                          .sup.4 According to ASTM Test Method                                          .sup.5 According to ASTM Test Method                                          .sup.6 Adhesion of facers to foam core was evaluated after laminate was       conveyed from oven and facers were allowed to cool to ambient temperature     The quality of the facer adhesion was judged by determining how difficult     it was to peel the facers from the foam.                                 

We claim:
 1. A laminate comprising at least one facing sheet adhered toa polyisocyanurate foam which comprises the reaction product of anorganic polyisocyanate, a blowing agent, a trimerization catalyst, and aminor amount of a polyol blend comprising(a) about 5 percent to about 95percent by weight of said blend of an alkylene oxide adduct of anaromatic amine of the formula ##STR7## wherein Z is a divalent aromaticradical, x, x', y, and y' each independently have an average value fromabout 1 to about 5, and each R is independently selected from the groupconsisting of hydrogen, alkyl or aryl, provided that the adduct iscapped with ethylene oxide units, and (b) about 5 percent to about 95percent by weight of said blend of an aromatic polyester polyol materialhaving a molecular weight of from about 150 to about 5,000.
 2. Thelaminate of claim 1 wherein said polyisocyanurate foam is reinforced byglass fibers.
 3. The laminate of claim 1 wherein said facing sheet is amember selected from the group consisting of an asphalt fiber glassfacer, an asphalt-saturated roofing felt, perlite board, aluminum foiland fiberboard.
 4. The laminate of claim 1 wherein said organicpolyisocyanate is a polymethylene polyphenylisocyanate.
 5. The laminateof claim 4 wherein said alkylene oxide adduct of an aromatic amine is anethylene oxide adduct of toluene diamine isomers of the formula ##STR8##wherein the average number of oxyethylene units per polyoxyethylenechain is from 2 to
 3. 6. The laminate of claim 1 wherein said organicpolyisocyanate is a mixture of components of the formula ##STR9##wherein n is an integer from 0 to 8 inclusive, and said mixture has: (a)a functionality of 2.1 to 3.2,(b) an equivalent weight between 120 and180, and (c) a viscosity at 25° C. between 150 and 2500 centipoises. 7.The laminate of claim 1 wherein said aromatic polyester polyol materialis a polyol mixture prepared by the transesterification, with a glycolof molecular weight from about 60 to 400, of a by-product fraction fromthe manufacture of dimethyl terephthalate, the major portion of saidfraction comprising about 15 to 70 weight percent of dimethylterephthalate, and about 85 to 30 weight percent of a mixture ofmonomethyl terephthalate, bi-ring esters and polymeric materials.
 8. Thelaminate of claim 7 wherein said by-product fraction from themanufacture of dimethyl terephthalate comprises a mixture of(a) about 40to 60 percent by weight of dimethyl terephthalate, (b) about 1 to 10percent by weight of monomethyl terephthalate, (c) about 1 to 2 percentby weight of terephthalic acid, (d) about 10 to 25 percent by weight ofbi-ring esters, (e) about 5 to 12 percent by weight of organic acidsalts, (f) about 18 to 25 percent by weight of polymeric materials, and(g) about 1 to 4 percent by weight of ash.
 9. The laminate of claim 1wherein said aromatic polyester polyol material is a polyol mixtureprepared by the transesterification, with a glycol of molecular weightfrom about 60 to about 400, of a residue remaining after dimethylterephthalate and methyl p-toluate have been removed from a dimethylterephthalate esterified oxidate reaction product, the major portion ofsaid residue comprising a mixture of methyl and benzyl esters of benzeneand biphenyl di- and tricarboxylic acids.
 10. The laminate of claim 1wherein said organic polyisocyanate is a polymethylenepolyphenylisocyanate, and said aromatic polyester polyol material is amember selected from the group consisting of(a) a polyol mixtureprepared by the transesterification, with a glycol of molecular weightfrom about 60 to 400, of a by-product fraction from the manufacture ofdimethyl terephthalate, the major portion of said fraction comprisingabout 15 to 70 weight percent of dimethyl terephthlate, and about 85 to30 weight percent of a mixture of monomethyl terephthalate, bi-ringesters and polymeric materials, (b) a polyol mixture prepared by thetransesterification, with a glycol of molecular weight from about 60 toabout 400, of a residue remaining after dimethyl terephthalate andmethyl p-toluate have been removed from a dimethyl terephthalateesterified oxidate reaction product, the major portion of said residuecomprising a mixture of methyl and benzyl esters of benzene and biphenyldi- and tricarboxylic acids, and (c) mixtures thereof, the equivalentratio of said organic polyisocyanate to said polyol blend being about1.5:1 to 6:1, and the weight ratio of said alkylene oxide adduct of anaromatic amine to said aromatic polyester polyol material being about1:9 to 1:1.
 11. The laminate of claim 10 wherein said alkylene oxideadduct of an aromatic amine is an ethylene oxide adduct of toluenediamine isomers of the formula ##STR10## wherein the average number ofoxyethylene units per polyoxyethylene chain is from 2 to
 3. 12. Thelaminate of claim 10 wherein(1) said polyol mixture (a) istransesterified with diethylene glycol and is characterized by aviscosity in cps at 25° C. of about 700 to 2500, a free diethyleneglycol content of from about 10 to 30 percent by weight of said mixture,a hydroxyl number within a range of from about 350 to 468, and an acidnumber of about 0.2 to 10, and (2) said polyol mixture (b) istransesterified with diethylene glycol and is characterized by aviscosity in cps at 25° C. of about 1,600 to about 2,800, a freediethylene glycol content of from about 20 to about 30 percent by weightof said mixture, a hydroxyl number within a range of from about 400 toabout 490, and an acid number of about 0.2 to about
 8. 13. The laminateof claim 12 wherein said alkylene oxide adduct of an aromatic amine ofthe blend is an ethylene oxide adduct of toluene diamine isomers of theformula ##STR11## wherein the average number of oxyethylene units perpolyoxyethylene chain is from 2 to
 3. 14. The laminate of claim 13wherein the weight ratio of said alkylene oxide adduct of an aromaticamine to said aromatic polyester polyol material is about 1:4 to 1:1.5.15. The laminate of claim 14 wherein said blowing agent is afluorocarbon and said trimerization catalyst comprises a mixture of atertiary amino phenol and an alkali metal carboxylate.
 16. The laminateof claim 15 wherein said trimerization catalyst comprises a mixture of2,4,6-tris(dimethylaminomethyl) phenol and potassium-2-ethyl hexoate inan equivalent ratio of about 0.4:1 to 2.5:1.
 17. The laminate of claim14 wherein said facing sheet is a member selected from the groupconsisting of an asphalt fiber glass facer, an asphalt-saturated roofingfelt, perlite board, aluminum foil and fiberboard.
 18. The laminate ofclaim 14 wherein said blowing agent is a halohydrocarbon selected fromthe group consisting of chlorinated hydrocarbons, fluorinatedhydrocarbons and mixtures thereof.
 19. The laminate of claim 18 whereinsaid facing sheet is a member selected from the group consisting of anasphalt fiber glass facer, an asphalt-saturated roofing felt, perliteboard, aluminum foil and fiberboard.
 20. The laminate of claim 18therein the weight ratio of said alkylene oxide adduct of an aromaticamine to said aromatic polyester polyol material is about 1:9 to 1:1.21. The laminate of claim 20 wherein said trimerization catalystcomprises a mixture of a tertiary amino phenol and an alkali metalcarboxylate.
 22. The laminate of claim 21 wherein said facing sheet is amember selected from the group consisting of an asphalt fiber glassfacer, an asphalt-saturated roofing felt, perlite board, aluminum foiland fiberboard.
 23. The laminate of claim 22 wherein said trimerizationcatalyst comprises a mixture of 2,4,6-tris(dimethylaminomethyl) phenoland potassium-2-ethyl hexoate.
 24. The laminate of claim 6 wherein saidblowing agent is a halohydrocarbon selected from the group consisting ofchlorinated hydrocarbons, fluorinated hydrocarbons and mixtures thereof.25. The laminate of claim 24 wherein said facing sheet is a memberselected from the group consisting of an asphalt fiber glass facer, anasphalt-saturated roofing felt, perlite board, aluminum foil andfiberboard.
 26. The laminate of claim 25 wherein the weight ratio ofsaid alkylene oxide adduct of an aromatic amine to said aromaticpolyester polyol material is about 1:9 to 1:1, and said trimerizationcatalyst comprises a mixture of a tertiary amino phenol and an alkalimetal carboxylate.
 27. The laminate of claim 7 wherein said organicpolyisocyanate is a polymethylene polyphenylisocyanate and said blowingagent is a halohydrocarbon selected from the group consisting ofchlorinated hydrocarbons, fluorinated hydrocarbons and mixtures thereof.28. The laminate of claim 27 wherein said facing sheet is a memberselected from the group consisting of an asphalt fiber glass facer, anasphalt-saturated roofing felt, perlite board, aluminum foil andfiberboard.
 29. The laminate of claim 28 wherein the weight ratio ofsaid alkylene oxide adduct of an aromatic amine to said aromaticpolyester polyol material is about 1:9 to 1:1, and said trimerizationcatalyst comprises a mixture of a tertiary amino phenol and an alkalimetal carboxylate.
 30. The laminate of claim 9 wherein said organicpolyisocyanate is a polymethylene polyphenylisocyanate and said blowingagent is a halohydrocarbon selected from the group consisting ofchlorinated hydrocarbons, fluorinated hydrocarbons and mixtures thereof.31. The laminate of claim 30 wherein said facing sheet is a memberselected from the group consisting of an asphalt fiber glass facer, anasphalt-saturated roofing felt, perlite board, aluminum foil andfiberboard.
 32. The laminate of claim 31 wherein the weight ratio ofsaid alkylene oxide adduct of an aromatic amine to said aromaticpolyester polyol material is about 1:9 to 1:1, and said trimerizationcatalyst comprises a mixture of a tertiary amino phenol and an alkalimetal carboxylate.
 33. The laminate of claim 10 wherein said blowingagent is a halohydrocarbon selected from the group consisting ofchlorinated hydrocarbons, fluorinated hydrocarbons and mixtures thereof,and said facing sheet is a member selected from the group consisting ofan asphalt fiber glass facer, an asphalt-saturated roofing felt, perliteboard, aluminum foil and fiberboard.
 34. The laminate of claim 33wherein said trimerization,catalyst comprises a mixture of a tertiaryamino phenol and an alkali metal carboxylate.
 35. The laminate of claim11 wherein said blowing agent is a halohydrocarbon selected from thegroup consisting of chlorinated hydrocarbons, fluorinated hydrocarbonsand mixtures thereof.
 36. The laminate of claim 35 wherein saidtrimerization catalyst comprises a mixture of a tertiary amino phenoland an alkali metal carboxylate.
 37. The laminate of claim 36 whereinsaid facing sheet is a member selected from the group consisting of anasphalt fiber glass facer, an asphalt-saturated roofing felt, perliteboard, aluminum foil and fiberboard.
 38. The laminate of claim 12wherein said blowing agent is a halohydrocarbon selected from the groupconsisting of chlorinated hydrocarbons, fluorinated hydrocarbons andmixtures thereof.
 39. The laminate of claim 38 wherein saidtrimerization catalyst comprises a mixture of a tertiary amino phenoland an alkali metal carboxylate.
 40. The laminate of claim 39 whereinsaid facing sheet is a member selected from the group consisting of anasphalt fiber glass facer, an asphalt-saturated roofing felt, perliteboard, aluminum foil and fiberboard.
 41. The laminate of claim 13wherein said blowing agent is a halohydrocarbon selected from the groupconsisting of chlorinated hydrocarbons, fluorinated hydrocarbons andmixtures thereof, and said facing sheet is a member selected from thegroup consisting of an asphalt fiber glass facer, an asphalt-saturatedroofing felt, perlite board, aluminum foil and fiberboard.
 42. Thelaminate of claim 41 wherein said trimerization catalyst comprises amixture of a tertiary amino phenol and an alkali metal carboxylate.